1. Field of the Invention
This invention relates, in general, to the saw grinding art and, in particular, to a method and apparatus for grinding the teeth of a circular saw to an improved contour.
2. Description of the Prior Art
The practice of grinding circular saws with abrasive wheels is known to those of ordinary skill in the art. Grinding equipment is made, for example, by the Vollmer Corporation of Dornhan, West Germany, and others. One of the major problems associated with conventional prior art carbide tipped steel cutting circular saws is that they cut slowly and wear out quickly. However, this difficulty was greatly reduced by the discovery that if the top of the face of the saw teeth are specially shaped to have a more negative rake angle relative to the rake of the rest of the tooth face, then efficiency was greatly approved. The special shaping typically involved multiple grinding operations in which several flat facets were formed in the top of the carbide tip. While the new shape was superior to the old shape, it was nevertheless time consuming to grind due to its multi-faceted contour. A description of this prior art shape may be found in an article by Pahlitzsch and Willemeit which appeared in Volume 58, Issue 4 of Werkstattstechneik (1968).
It is presently believed that a curved surface may be used to approximate the new German geometry. However, a method and apparatus for automatically forming such an improved contour is not believed to be available at the time of this invention. Therefore, the present invention arose to fulfill the need for such equipment. A principal advantage of generating a more negative rake surface in this manner is that it saves several grinding steps over the previous method necessary to form the German geometry. By avoiding extra grinding steps, it is possible to realize higher machine efficiencies and lower operating costs.